Hello Friends,
I am right now working on a project that has a database with over 100 tables in a database. Because of extreme time constraints the developers didn't build in any relationships or constraints between or in the tables. Now I need to remodel the database such that the database is more structured and normalized. I don't have much knowledge about the database design since it is a 2 year old application and the person who developed the database is now gone. I know remodelling the database would require knowledge of the existing database and business rules.
I was wondering if there are any tools that could suggest or discover relationships between tables. For eg. Lets say there are two tables named 'Customer' and 'Order'. I notice that there is a column named 'id' in Customer and a column named 'customer_id' in Order. So I ask the tool to discover a relationship between id and customer_id and it tells me that there is a one-one or one-many or no relationship by comparing values. I heard ERWin would be able to do that but thats expensive. Please do let me know asap.

What's the database? Oracle? SQL Server?

SQL Server

for starters, try Visio. It can often do an acceptable job of reverse engineering a database.